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You may not have known that it exists, but there is a National Children’s Day. Though it originally started with religious undertones in the 19th century, in the modern day and age, it’s a good way to remember how we can improve health care access and immunization for kids in the U.S.

According to Childstats.gov, there are some 74 million people under the age of 18 in the U.S., and nine million — or 12 percent — of those kids are uninsured. The Centers for Disease Control and Prevention (CDC) states that there are about 6.6 percent of children who lack health insurance, while 3.8 percent of kids don’t have “a usual source of health care.” The CDC also notes that the most common forms of death for children between 1 and 14 years of age are accidents, congenital malformations/deformations, or chromosomal abnormalities. Cancer is also on that list.

As kids grow and develop, it’s essential to send them to the doctor for regular check-ups in order to catch any issues at the start. “The health of children depends at least partially on their access to health services,” the 2013 Key National Indicators of Well-Being report states. Simple things that parents can regularly monitor include any significant weight gain or loss, sleep problems, fevers, rashes, or breathing problems.

Vaccinating your kids is also critical to their development and overall health. The same 2013 Well-Being data state that about 78 percent of children aged 19 to 35 months had received the six-vaccine series, but children living in families who were below the poverty level had less of a chance to be vaccinated. Vaccination among children aged 13 to 17 years has increased since 2006, but “coverage with vaccines recommended at 11 or 12 years of age remains low, especially for human papillomavirus (HPV) vaccine,” the report says.

On its website, the CDC lists the recommended vaccines for children ages 0 to 18 as the Hepatitis B, rotavirus, tetanus and diphtheria, pneumococcal, poliovirus, and influenza vaccines, among others.

National Children’s Day was first conceived by Reverend Charles H. Leonard, a pastor of a First Universalist church in Massachusetts, in 1856. The original Children’s Day was a religious one: it was meant to set aside a Sunday to dedicate kids to Christianity, and to remind parents to raise their kids piously. Today, make National Children’s Day a reminder to get your kids vaccinated, and to get checked up at the doctor and dentist.